The Chattanooga Zoo in Tennessee, US, has announced that a female Komodo dragon has produced offspring without the assistance of a male.
The three offspring were born on August 4, 2019. DNA tests were performed to determine whether Charlie, the first-time mother, had reproduced with the help of a male resident of the zoo, called Kadal, or whether she did it without the need of a male - a phenomenon known as parthenogenesis.
Although the male Komodo dragon made multiple attempts to mate with her, at no time did she seem interested in pairing with him. However, as the zoo announced in September, the female laid several eggs and, gave birth to the three hatchlings without previous sexual contact with the male.
Parthenogenesis does not occur in mammals, but invertebrates are a different case. Although this phenomenon rarely occurs in reptiles, it is far from unheard of. Last year, a Chinese water dragon female, which had previously been isolated from males since it reached sexual maturity, gave birth at the Smithsonian National Zoo, in the US.
"The DNA results show that the offspring were, in fact, reproduced through parthenogenesis,” wrote the zoo on their Instagram account.
“Although Kadal and Charlie were placed together in the hopes of breeding, the Chattanooga Zoo staff is very excited to witness this monumental work of nature and be part of such an important conservation program,” they added in their press release.
According to the zoo, Komodo dragons can live isolated lives and female dragons have evolved so that they can reproduce through either sex or parthenogenesis.
Reptiles use a diverse selection of sex chromosomes from the mammals. Female Komodo dragons carry WZ sex chromosomes, while males carry the ZZ type. When parthenogenesis occurs, the mother can only create WW or ZZ eggs. Since eggs with WW sex chromosomes are not viable, only ZZ eggs remain to produce male offspring.
The pups, which are already six-months-old, are called Onyx, Jasper and Flint and are growing rapidly and healthily. Visitors to the Chattanooga Zoo can see them in the Forests of the World habitat building on Saturday and Sunday from 9 a.m. until 5 p.m.
Komodo dragons are undoubtedly the largest lizard species and can grow up to three meters long. Despite their exceptional success as hunters, restricting their habitat threatens their long-term future.
Reference: The Chattanoogan.com